If you are developing such a client with the Thrift API, see API for what data structures and method calls are available, and ThriftExamples for examples.

The purpose of using Thrift in Cassandra was to allow portable (across programming languages) access to the database. Thrift accomplishes this by generated source code for the programming language in question based on a Thrift IDL file describing the service (see here).

Let's see how we can use a generated python client to access Cassandra.